Space extreme design

This paper is an introduction to the following five articles, that have been conceived together as one chapter on habitability consideration for outer space habitations. Those contributions are made from authors in different fields, cultures and countries working with the Extreme-Design.eu research group. Projects, theories and requirements are referred to the context of outer space habitats, where for the love of knowledge, human beings are living under extreme condition. The group purpose is to apply holistic approach (using both scientific and humanity discipines) towards space habitat design to support human cultural experience and improve technical reliability. Space Anthropology, Space Design, Space Art and Space Psychology are the established disciplines here considered to have a bearing on astronaut reliability. With multidisciplinary contributions, natural design philosophy- and human-centred design, these papers aim of collecting a range of solutions and innovative ideas on how to increase habitability in space.     

Mining hot calling contexts in small space

Calling context trees (CCTs) associate performance metrics with paths through a program's call graph, providing valuable information for program understanding and performance analysis. In real applications, however, CCTs might easily consist of tens of millions of nodes, making them difficult to analyze and also hurting execution times because of poor access locality. For performance analysis, accurately mining only hot calling contexts may be more useful than constructing an entire CCT with millions of uninteresting paths, because the distribution of context frequencies is typically very skewed. In this article, we show how to exploit this property to considerably reduce the CCT size, introducing a novel runtime data structure, called hot CCT (HCCT), in the spectrum of representations for interprocedural control flow. The HCCT includes only hot nodes and their ancestors in a CCT and can be constructed independently from it by using fast, space‐efficient algorithms for mining frequent items in data streams. With this approach, we can distinguish between hot and cold contexts on the fly while obtaining very accurate frequency counts. We show, both theoretically and experimentally, that the HCCT achieves a similar precision as the CCT in a space that is several orders of magnitude smaller and roughly proportional to the number of hot contexts. Our approach can be effectively combined with previous context‐sensitive profiling techniques, as we show for static bursting. We devise an implementation as a plug‐in for the gcc compiler that incurs a slowdown competitive with the gprof call‐graph profiler while collecting finer‐grained profiles. Copyright © 2015 John Wiley & Sons, Ltd.     

The impact of an innovative instructional intervention on the acquisition of oral presentation skills in higher education

The present study focuses on the design and development of an instructional approach to develop oral presentation skills. The theoretical base builds on the social cognitive perspective, and self-regulated learning. The aim of the study is to investigate whether the design of a multimedia-based instructional format - comprising of a standardised multimedia instruction, practical activities and feedback - will enhance oral presentation skills. In the study, the differential effect of three ‘modes of feedback’ on performance has been researched. The results reveal that oral presentation skills did improve significantly after the instruction. The multimedia nature of the design was favoured by all participants. In contrast, no significant impact of feedback was found. Nevertheless, feedback proved to be a useful process that was highly welcomed by participants.     

Gender and ergonomics: a case study on the 'non-formal' work of women nurses

Women's work activities are often characterised by 'non-formal actions' (such as giving support). Gender differences in ergonomics may be due to this peculiarity. We applied the method of organisational congruencies (MOC) to ascertain the 'non-formal' work portion of nurses employed in three hospital units (haematology, emergency room and general medicine) during the three work shifts in a major University Hospital in Rome, Italy. We recorded a total of 802 technical actions performed by nine nurses in 72 h of work. Twenty-six percent of the actions in direct patient's care were communicative actions (mainly giving psychological support) while providing physical care. These 'double actions' are often not considered to be a formal part of the job by hospital management. In our case study, the 'non-formal' work of nurses (psychological support) is mainly represented by double actions while taking physical care of the patients. The dual task paradigm in gender oriented research is discussed in terms of its implications in prevention in occupational health. PRACTITIONER SUMMARY: The main purpose of the study was to assess all the formal and non-formal activities of women in the nursing work setting. Offering psychological support to patients is often not considered to be a formal part of the job. Our case study found that nurses receive no explicit guidelines on this activity and no time is assigned to perform it. In measuring the burden of providing psychological support to patients, we found that this is often done while nurses are performing tasks of physical care for the patients (double actions). The article discusses the significance of non-formal psychological work load of women nurses through double actions from the ergonomic point view.     

Queen Control or Queen Signal in Ants: What Remains of the Controversy 25 Years After Keller and Nonacs’ Seminal Paper?

Ant queen pheromones (QPs) have long been known to affect colony functioning. In many species, QPs affect important reproductive functions such as diploid larvae sexualization and egg-laying by workers, unmated queens (gynes), or other queens. Until the 1990s, these effects were generally viewed to be the result of queen manipulation through the use of coercive or dishonest signals. However, in their seminal 1993 paper, Keller and Nonacs challenged this idea, suggesting that QPs had evolved as honest signals that informed workers and other colony members of the queen’s presence and reproductive state. This paper has greatly influenced the study of ant QPs and inspired numerous attempts to identify fertility-related compounds and test their physiological and behavioral effects. In the present article, we review the literature on ant QPs in various contexts and pay special attention to the role of cuticular hydrocarbons (CHCs). Although the controversy generated by Keller and Nonacs’ (Anim Behav 45:787–794, 1993) paper is currently less intensively debated, there is still no clear evidence which allows the rejection of the queen control hypothesis in favor of the queen signal hypothesis. We argue that important questions remain regarding the mode of action of QPs, and their targets which may help understanding their evolution.     

A capacitance and optical method for the static and dynamic characterization of micro electro mechanical systems (MEMS) devices

As the micro technology field expands, the need of simple and standardized procedures to precisely evaluate device functionality, realibility and quality of micro electro mechanical systems devices increases. In this paper the application of two empirical methods suitable for the static and the dynamic characterization of micrometersized structures is proposed. The first methodology is based on capacitance measurements and finds simple application in case of comb-finger actuated devices. The second one is based on the Doppler phenomenon combined with laser optical interferometry allowing the characterization of a wide range of structures. The methodologies are applied to a reliability test structure specifically designed at STMicroelectronics for studying the fatigue behaviour of the structural material involved in the fabrication of their commercial products. This case of study highlights how the techniques may be coupled to usual design approaches for completing and verifying the information given by theory and simulations; thus improving the entire development cycle.     

Effect of the Grain Boundary Thermal Expansion Coefficient on the Fracture Toughness in Silicon Nitride

The effect of thermal expansion mismatch stress between silicon nitride and different grain boundary phases on the fracture toughness of silicon nitride was investigated. Different sintering aids in the Y-Mg-Si-Al-O-N system produced silicon nitride specimens with very similar micro- structures but different grain boundary phase compositions and different values of fracture toughness. The fracture toughness of the silicon nitride increased as the thermal expansion coefficient of the grain boundary phase increased. The presence of tensile residual stress at the grain boundary caused by thermal expansion mismatch between the silicon nitride and the grain boundary phase enhanced crack deflection and grain bridging.     

Hydrogen Production from Ethanol Steam Reforming Over Ni/CeO2 Nanocomposite Catalysts

The organic polymer chitosan was used as the polymeric precursor for the synthesis of Ni/CeO₂ nanocomposite catalysts. The materials were characterized by N₂ physisorption, H₂ chemisorption, AA, XRD, TGA, TPR, SEM and TEM analyses. The catalysts provide very good reactivity in ethanol steam reforming compared to the conventional Ni/CeO₂ catalyst prepared by the impregnation method using a commercial support. High hydrogen selectivity (>75%) was obtained on Ni/CeO₂ catalysts by operating at a temperature range of 325–500 °C and a H₂O/C₂H₅OH molar ratio of 3. It was verified that the catalytic behavior could be influenced depending on the experimental conditions employed.     

Energy calculations and analysis of HIV-1 protease-inhibitor crystal structures

The interactions between HIV–1 protease and its boundinhibitors have been investigated by molecular mechanics calculationsand by analysis of crystal structures of the complexes in orderto determine general rules for inhibitor and substrate bindingto the protease. Fifteen crystal structures of HTV–1 proteasewith different peptidomimetic inhibitors showed conservationof hydrogen bond interactions between the main chain C=O andNH groups of the inhibitors and the C=O and NH groups of theprotease extending from P3 C=O to P3' NH. The mean length ofthe hydrogen bonds between the inhibitor and the flexible flapsand the conserved water molecule (2.9 À) is slightlyshorter than the mean length of hydrogen bonds between the inhibitorand the more rigid active site region (3.1 À) of theprotease. The two hydrogen bonds between the conserved waterand P2 and P1' carbonyl oxygen atoms of the inhibitor are theshortest and are predicted to be important for the tight bindingof inhibitors. Molecular mechanics analysis of three crystalstructures of HIV-1 protease with different inhibitors withindependent calculations using the programs Discover and Brugelgave an estimate of 56-68% for the contribution of all the inhibitormain chain atoms to the total calculated protease–inhibitorinteraction energy. The contribution of individual inhibitorresidues to the interaction energy wascalculated using Brugel.The main chain atoms of residue P2 had a consistently largefavorable contribution to the total interaction energy, probablydue to the presence of the two short hydrogen bonds to the flexibleflap. The contribution of individual inhibitor side chains dependedon the size of the side chain and the presence of specific hydrogenbond interactions with the protease.     

Sulfur-substituted and α-methylated fatty acids as peroxisome proliferator-activated receptor activators

FA with varying chain lengths and an α-methyl group and/or a sulfur in the β-position were tested as peroxisome proliferator-activated receptor (PPAR)α,-δ(β), and-γ ligands by transient transfection in COS-1 cells using chimeric receptor expression plasmids, containing cDNAs encoding the ligand-binding domain of PPARα,-δ, and-γ. For PPARα, an increasing activation was found with increasing chain length of the sulfur-substituted FA up to C₁₄-S acetic acid (tetradecylthioacetic acid=TTA). The derivatives were poor, and nonsignificant, activators of PPARδ. For PPARγ, activation increased with increasing chain length up to C₁₆-S acetic acid. A methyl group was introduced in the α-position of palmitic acid, TTA, EPA, DHA, cis9,trans11CLA, and trans10,cis12 CLA. An increased activation of PPARα was obtained for the α-methyl derivatives compared with the unmethylated FA. This increase also resulted in increased expression of the two PPARα target genes acyl-CoA oxidase and liver FA-binding protein for α-methyl TTA, α-methyl EPA, and α-methyl DHA. Decreased or altered metabolism of these derivatives in the cells cannot be excluded. In conclusion, saturated FA with sulfur in the β-position and increasing carbon chain length from C₉−S acetic acid to C₁₄−S acetic acid have increasing effects as activators of PPARα and-γ in transfection assays. Furthermore, α-methyl FA derivatives of a saturated natural FA (palmitic acid), a sulfur-substituted FA (TTA), and PUFA (EPA, DHA, c9,t11 CLA, and t10,c12 CLA) are stronger PPARα activators than the unmethylated compounds.